An official website of the United States government
Here’s how you know
Official websites use .gov
A .gov website belongs to an official government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.
Tunneling Characteristics and Low Frequency Noise of High-Tc Superconductor/Noble-Metal Junctions
Published
Author(s)
Yizi Xu, John (Jack) W. Ekin
Abstract
We report extensive measurements of transport characteristics and low-frequency resistance noise of c-axis YBCO/Au junctions. The dominant conduction mechanism is tunneling at low temperatures. The conductance characteristic is asymmetric, and the conductance minimum occurs at a non-zero voltage. These features can be qualitatively explained by modeling by YBCO/Au interface with a Schottky barrier. The model shows the YBCO surface behaves like a p-type semiconductor, with a Fermi degeneracy of about 0.1 eV. This is consistent with a carrier density of 3 x 10 21 cm-3, and a band mass of 2.6 times that of the free-electron mass. The barrier-height is approximately 1.0 eV. We show that interface states and disorder play an important role in determining the conductance characteristics. Low-frequency noise measurements of many junctions with contact areas ranging from 4 υm2 to 64 υm2, over a wide temperature and bias range, indicate that the noise figure for engineering design may be expressed as a normalized resistance fluctuation δR/Rapproximately equal}6×10-4/√Hz at 10 Hz.
Citation
Physical Review B (Condensed Matter and Materials Physics)
Xu, Y.
and Ekin, J.
(2004),
Tunneling Characteristics and Low Frequency Noise of High-Tc Superconductor/Noble-Metal Junctions, Physical Review B (Condensed Matter and Materials Physics)
(Accessed April 26, 2025)